1. Field of the Invention
The present invention relates to an electromagnetic bandgap (EBG) structure, and more particularly, to an EBG interrupting transmission of wideband noise and a manufacturing method thereof.
2. Description of the Related Art
Recently marketed multimedia devices are designed such that devices having various signal characteristics such as digital, analog, radio frequency (RF), and the like are combined on a single printed circuit board (PCB), so as to reduce size and weight of the multimedia devices.
In the multimedia devices, a noise induced from one device easily propagates to another device through the PCB being shared. According to an increase in an operation speed of the device and a transmission rate of signal lines, frequency characteristics of the propagated noise are becoming wideband.
The wideband noise may reduce a noise margin necessary for power stabilization of a digital device. Also, the wideband noise may increase undesired reduction in a signal amplitude, overshot, and jitter as being coupled with the signal lines. In case of an RF device, reception sensitivity may be reduced due to the wideband noise. An apparatus capable of covering frequency regions from a megahertz (MHz) band to a gigahertz (GHz) band is necessary to isolate such a wideband noise.
Conventional technologies for isolating the wideband noise is ineffective for size reduction and have a relatively narrow noise isolation frequency band. Therefore, an electromagnetic bandgap structure needs to be enlarged in order to reduce the noise isolation frequency band to the MHz band.
To make the noise isolation frequency appropriate for a wideband, electromagnetic bandgap structures having different noise isolation frequencies need to be used in to combination, which may also increase the entire size. Accordingly, there is a desire for a minimized apparatus capable of a noise from the MHz band while having wideband noise characteristics.